diff --git a/app/controllers/admin/asks_controller.rb b/app/controllers/admin/asks_controller.rb
index eb031dd..2e863a3 100644
--- a/app/controllers/admin/asks_controller.rb
+++ b/app/controllers/admin/asks_controller.rb
@@ -156,7 +156,7 @@ class Admin::AsksController < OrbitAdminController
     redirect_to "/#{locale}/admin/asks/category_setting"
   end
   def process_format_text(text,custom_fields)
-    customs = text.scan(/<tr.*{custom}.*<\/tr>/m).uniq
+    customs = text.scan(/<tr(?:(?!<tr).)+\{custom\}(?:(?!<tr).)+<\/tr>/m).uniq
     if customs.length != 0
       custom_exist_nums = []
       custom_exists = text.scan(/{custom\d+}/)